[jester]

The difference is the following:

Machining is where you have large solid piece of metal. And you need to mill and drill and grind that piece of metal into the shape of what it is your are building.

An example most bolts are made through a milling process. Look at the grooves and holes and such. That is an example of machining.

Then we have forging; this is where the item is more or less build in a mold, some machining is normaly used after this process to finish the product.

Then stamping, this is nothing more than a piece of sheet metal and it is placed in a press. The press comes down "STAMPING" the part into the shape you are trying to get.

Some examples:

AKM uses a stamped reciver, the original AK47 used a Milled reciever.

M16 is forged with some milling

L1A1 forged with milling

Sten, Sterling, PPsH series stamped

M1a1 Thompson, milled
M1 Garand Milled
MP 38 Machined
MP40 stamped

MG 34 machined
MG 40 stamped

Most pistols are forged with some mill work done unless they are polymers of course.

Basicaly the stamped item is less robust, but it is also completed by a less skiller person with 1 action, the falling of a punch press. The press falls on the metal and "WHAM!" your part is made.

Forging, your metal needs to be really hot, you have to have tools, maybe a mold and then finish work.

Milling, there is ALOT of wastage, and you need alot of equipment machines and such and skiller people to operated them.

And the time involved as well.